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ARM, previously Advanced RISC Machine, originally Acorn RISC Machine, is a family of RISC architectures for computer processors, configured for various environments. Arm Limited (formerly Arm Holdings) develops the architecture and licenses it to other companies, who design their own products that implement one of those architectures—including systems-on-chips (SoC) and systems-on-modules (SoM) that incorporate memory, interfaces, radios, etc. It also designs cores that implement this instruction set and licenses these designs to a number of companies that incorporate those core designs into their own products.


Processors that have a RISC architecture typically require fewer transistors than those with a complex instruction set computing (CISC) architecture (such as the x86 processors found in most personal computers), which improves cost, power consumption, and heat dissipation. These characteristics are desirable for light, portable, battery-powered devices—including smartphones, laptops and tablet computers, and other embedded systems[1][2][3]—but are also useful for servers and desktops to some degree. For supercomputers, which consume large amounts of electricity, ARM is also a power-efficient solution.[4]

With over 130 billion ARM processors produced,[5][6][7][8] As of 2019, ARM is the most widely used instruction set architecture (ISA) and the ISA produced in the largest quantity.[9][2][10][11][12] Currently, the widely used Cortex cores, older "classic" cores, and specialized SecurCore variants are available for each of these to include or exclude optional capabilities.

Market competition

Arm's main CPU competitors in servers include IBM, Intel and AMD.[13] Intel competed with Arm-based chips in mobile, but Arm no longer has any competition in that space (however, vendors of actual Arm-based chips compete within that space). Arm's main GPU competitors include mobile GPUs from American and Japanese technology companies Imagination Technologies (PowerVR), Qualcomm (Adreno), and increasingly Nvidia and Intel. Despite competing within GPUs, Qualcomm and Nvidia have combined their GPUs with Arm-licensed CPUs.


Arm had a primary listing on the London Stock Exchange and was a constituent of the FTSE 100 Index. It also had a secondary listing on NASDAQ. However Japanese telecommunications company SoftBank Group made an agreed offer for Arm on 18 July 2016, subject to approval by Arm's shareholders, valuing the company at £24.3 billion.[14] The transaction was completed on 5 September 2016.[15][16]

On 13 September 2020, it was announced that Nvidia would buy Arm from SoftBank for $40 billion, subject to regulatory approval, with the latter acquiring a 10% share in Nvidia.[17][18][19] In December 2021, the Federal Trade Commission filed a lawsuit to block the deal, claiming that Nvidia's ownership of ARM architecture could stifle innovation and competition in the processor market.[20]

Apple and ARM

In the late 1980s, Apple Computer and VLSI Technology started working with Acorn on newer versions of the ARM core. In 1990, Acorn spun off the design team into a new company named Advanced RISC Machines Ltd.,[21][22][23] which became ARM Ltd when its parent company, Arm Holdings plc, was floated on the London Stock Exchange and NASDAQ in 1998.[24] Apple invested US$3 million for a 30% stake in the venture.[23] The new Apple-ARM work would eventually evolve into the ARM6, first released in early 1992. Apple used the ARM6-based ARM610 as the basis for their Newton PDA. However, with disappointing sales, Apple closed down the Newton Systems Group in 1998 and sold its stake in ARM for $800 million in desperately needed cash.[25]

In 2001, Apple released the first iPod, which used a ARM-based processor from PortalPlayer and ran an operating system designed by Pixo, which was co-founded and staffed by former Newton employees.[25][26]

Apple licensed ARM technology for the A4, A5, and A5X and other early processors used in its iPhone and iPad lines. However, Apple acquired P.A. Semi for $278 million in April 2008 to bring fabless processor design in-house to the company.[27] The Apple A6 contained a custom CPU designed internally at Apple (called "Swift") instead of one licensed from ARM.[28]


  1. "Some facts about the Acorn RISC Machine" Roger Wilson posting to comp.arch, 2 November 1988. Retrieved 25 May 2007.
  2. 2.0 2.1 Hachman, Mark. "ARM Cores Climb Into 3G Territory", ExtremeTech, 14 October 2002. Retrieved on 24 May 2018. (in en-US) 
  3. Turley, Jim. "The Two Percent Solution", Embedded, 18 December 2002. Retrieved on 24 May 2018. (in en) 
  4. Fujitsu drops SPARC, turns to ARM for Post-K supercomputer (20 June 2016). Retrieved on 18 December 2016.
  5. Architecting a smart world and powering Artificial Intelligence: Arm (en) (2019). Retrieved on 2020-04-08.
  6. Ltd, Arm. Microprocessor Cores and Technology – Arm (en). Retrieved on 2020-04-08.
  7. Enabling Mass IoT connectivity as Arm partners ship 100 billion chips (en). Retrieved on 2020-04-08. “the cumulative deployment of 100 billion chips, half of which shipped in the last four years. [..] why not a trillion or more? That is our target, seeing a trillion connected devices deployed over the next two decades.”
  8. Ltd, Arm. Microprocessor Cores and Technology – Arm (en). Retrieved on 2020-04-08.
  9. MCU Market on Migration Path to 32-bit and ARM-based Devices: 32-bit tops in sales; 16-bit leads in unit shipments. IC Insights (25 April 2013). Retrieved on 1 July 2014.
  10. Turley, Jim (2002). The Two Percent Solution.
  11. ARM Holdings eager for PC and server expansion (1 February 2011).
  12. Kerry McGuire Balanza (11 May 2010). ARM from zero to billions in 25 short years. Arm Holdings. Retrieved on 8 November 2012.
  13. Merritt, Rick. Cavium Flexes ARM Server Upgrade: 14nm ThunderX2 will pack 54 cores.
  14. BBC. “ARM chip designer to be bought by Japan's SoftBank 18 July 2016. Retrieved 22 July 2016.
  15. "SoftBank finally completes £24bn ARM takeover", Silicon Republic, 5 December 2016. 
  16. Acquisition of ARM Holdings plc. by SoftBank Group Corp..
  17. Moorhead, Patrick. It's Official- NVIDIA Acquires Arm For $40B To Create What Could Be A Computing Juggernaut (en).
  18. NVIDIA to Acquire Arm for $40 Billion, Creating World's Premier Computing Company for the Age of AI (en) (13 September 2020).
  19. Rosoff, Matt. "Nvidia to buy Arm Holdings from SoftBank for $40 billion", CNBC, 13 September 2020. 
  20. FTC sues to block Nvidia's $40B acquisition of Arm by Mike Peterson, AppleInsider. 2021-12-02.
  21. ARM milestones, ARM company website. Retrieved 8 April 2015
  22. Jason Andrews. "Co-verification of hardware and software for ARM SoC design", Elsevier, pp. 69. “ARM started as a branch of Acorn Computer in Cambridge, England, with the formation of a joint venture between Acorn, Apple and VLSI Technology. A team of twelve employees produced the design of the first ARM microprocessor between 1983 and 1985.” 
  23. 23.0 23.1 Weber, Jonathan. "Apple to Join Acorn, VLSI in Chip-Making Venture", Los Angeles Times, 28 November 1990. Retrieved on 6 February 2012. “Apple has invested about $3 million (roughly 1.5 million pounds) for a 30% interest in the company, dubbed Advanced Risc Machines Ltd. (ARM) [...]” 
  24. ARM Corporate Backgrounder. ARM Limited. Archived from the original on 4 October 2006.
  25. 25.0 25.1 How The Newton And ARM Saved Apple From Death, The CPU Shack Museum. 2010-10-26.
  26. Little-known startup was behind iPod's easy-to-use interface / Firm's founder now working on the latest handhelds by Matthew Yi, San Francisco Chronicle. 2004-08-16.
  27. "Apple Buys Chip Designer", Forbes. Retrieved on 2008-04-23. 
  28. The iPhone 5 Review - Decoding Swift. AnandTech (October 16, 2012). Retrieved on October 17, 2012.

See also

External links


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